Bit Synchronizers

Model 270 Multi-Channel Bit Synchronizer with Digital IO

The GDP Model 270 Multi-Channel (8 or 16 Channels) Bit Synchronizer unit with Digital I/O is a compact state-of-the-art high-performance device that is designed to extract usable digital data and provide an output clock from serial digital input streams.  The optimized digital design of this unit affords the highest performance characteristics currently available. Eight additional channels can be added (16 channels total) to the box as an option.

The Model 270 includes eight or sixteen independent channels that each have both TTL and RS-422 inputs and outputs. The unit includes programmable loop bandwidths from 0.05% to 1.6%. When searching for the signal, acquisition is attainable in as little as 40 bits. At the widest LBW the unit will track the signal to 15% of the input rate. Synchronization is maintained in the absence of transitions for a period of at least 128 bits.

Encoded data streams are processed to expose the raw information. IRIG-106 Randomized data is decoded to its native form. Both forward and reverse sequences are accommodated.

To further assure synchronization to the intended data stream, the optional Frame Pattern Detector may be invoked. Up to a 64-bit long pattern is detected. Maintaining synchronization with this pattern at the programmed repetition rate and synchronization strategy produces a lock signal. The unit also includes an APC (Automatic Polarity Correction) mode. In this mode, the output polarity of the data will be corrected.

When the input bit rate is expected to be changing, use the optional Auto Bit Rate Scan. Up to 8 bit rates, input codes and Synchronization patterns can be programmed. The bit synchronizer automatically finds the appropriate setting from the list and locks to the input signal. To add accuracy to the lock decision, the Frame Pattern Detector be included in the test. Status for each of the streams along with selected bit rate and deviation are displayed on the front panel.

  1. 8 Independent Channels
  2.      • 8 Additional Channels 16 Total (Optional)
  3. Bit Rates
  4.      • 5 bps to 20 Mbps (Std)
         • 5 bps to 32 Mbps (Option)
  5. Auto Bit-Rate Scan (Option)
  6. Tracking Range up to 15% Accepts NRZ-L/M/S, RNRZ-(F/R), Biø-L/M/S, DM-M/S>codes
  7. 2 Input Sources per Channel
  8.      • One TTL & One RS-422
  9. 2 Outputs per Channel
  10.      • One TTL & One RS-422
  11. Selectable Data/Clock Test Point on Front Panel (BNCs)
  12. Status Indicators for Sync
  13. IRIG-106 Derandomizer
  14. Frame Pattern Detector with Programmable Sync Strategy and APC (Optional)
  15. Remote Control via.
  16.      • RS-232 (std)
         • RS-485 (Option)
         • Ethernet (Option)
  17. 3.5 -inch (2U) High Chassis
Signal Inputs
Two Selectable Digital Inputs; (1) RS-422 Input, (1) TTL
Input Impedance
TTL: 50 ohm (std) or 75 ohm (opt) RS-422 (120 ohm/None)
IRIG-106 (Forward/ Reverse)

Bit Rate Range
5 bps to 20 Mbps (5 bps to 32 Mbps Optional)
Bit Rate Tuning Resolution
X.XXXEN (1≤N≤7)
Loop Bandwidths
Programmable from 0.05% to 1.6%
Up to 15%
Sync Retention
128 bits minimum without transitions, LBW1.
Frame Pattern Detector
Detection of up to 64 bits (Optional) Programmable Synchronization Strategy (S/C/L) with APC

Two Outputs; (1) RS-422 Input, (1) TTL
Output Impedance
TTL: 50 ohm (std) or 75 ohm (optional) RS-422 - 120 Ohm or None
IRIG-106 (Forward/Reverse)
Output Polarity normal / inverted (Data & Clock).
Front Panel LEDs
LED Lock Indicator for each channel Display
Front Panel Display
Lock Status, Deviation, Bit Rate Lock for each channel
Auto Scan (Optional)
Scan up to 8 Bit Rates/Codes/Sync Patterns for each channel.